1. Field of Invention
The invention relates to asphaltic compositions which are derived by thermally decomposing organic waste material and, more particularly, to a method for preparing asphalt compositions which are suitable for use as a binder material in the construction of asphalt paving structures.
2. Description of Prior Art
Pyrolysis processes are known for chemically converting organic materials to other useful chemical products. Aside from the conversion of raw materials, such as coal, consideration has been given to the conversion of solid organic wastes. See, for example, "Industrial Solid Wastes Management," pages 356-406, the Proceedings of the National Industrial Solid Wastes Management Conference, sponsored by the University of Houston and Bureau of Solid Waste Management on Mar. 24-26, 1970.
It is also known that agriculture is one of the largest single sources of potentially useful carbohydrate type wastes. Recent progress on the conversion of agricultural wastes to an industrial fuel oil is described in Symposium: Processing Agricultural and Municipal Wastes, edited by G. E. Inglett, published in Westport, Connecticut by the Avi Publishing Company, Inc., 1973. In Table 8.3, page 90, bovine manure is converted to oil in the presence of anthracene oil solvent.
U.S. Pat. No. 3,338,849 discloses the incorporation of waste material, i.e., reclaimed rubber, into asphalt composition for use in paving roads and other surfaces. Scrap polyethylene is used to increase the dispersibility of the rubber in the asphalt.
U.S. Pat. No. 3,960,793 discloses blending "reject polypropylene," a waste product, with asphalts to produce adhesives and molding compositions. The asphalts may be treated with sulfur or halogen-containing materials to increase their consistency.
Given the proliferation of used rubber tires, plastic and paper packaging materials, one-way plastic and paper containers, by-product and substandard polymers, solid organic wastes generally, and the like, improved methods of recovering potential hydrocarbon values contained therein are needed, particularly in view of the increasing scarcity of oil and natural gas. The valuable hydrocarbons in such materials would be better utilized if an economically attractive method could be devised for transforming them into useful liquid, solid and/or gaseous hydrocarbon products having utility as fuel or as substitutes for petroleum-derived raw materials.